Women's cultural role in physical exursion

A woman tried to invade a sumo ring in Japan today, which if she had succeeded according to custom would have made the ring unclean. In the article it says Japanese women were also once not allowed to climb mountains or enter mines. Maybe it's just because I had just read this blog about the Masai people (where women really get the short end of the stick), but it just makes me sad how women are considered unclean, tainted, not as good as men, in so many cultures, and how that is reflected in what chores are traditionally assigned to them in different cultures.
Most women were banned across the board from sports until recently, but it was expected of them to do back breaking labor in the fields, or with livestock, or simply building shelter for their families. They have to do all the hard, boring stuff, but men get to have all the fun activities. It is still an issue in some places to allow women to join the country's military (see my earlier post).
Yes, traditionally men go out and hunt for women and children. They go to war. They put their lives on the line for their families. But that shouldn't make women automatically second-class citizens, especially in a culture where food is provided primarily by agriculture and/or livestock (something both genders can do equally well), and war is no longer a common problem.
For the Masai this is not the case. Even though they are technically pastoralists, the men still go on cattle raids regularly and are gone from home a lot risking their lives. But in contrast, even though the Japanese (and the U.S.) have been in major wars in the past 60 years, they've moved beyond their traditional gender roles in so many other ways one would think they'd be able to move past restriction of women in certain arenas or activities as well, and especially using the "cleanliness" of a person's gender as the main criteria.
At the same time, I believe in upholding and preserving traditions and customs. It's also true Japan had very strict gender roles until much more recently that the U.S. or U.K., and really in the end the act of excluding women from the Sumo wrestling ring isn't a huge deal. It's just the overarching trend of looking at women as second-rate when it comes to physical abilities or activities that irks me.